Re: What's left over.

Karim Yaghmour
2002-10-31T03:04:04Z

Linus Torvalds wrote:
> > Linux Trace Toolkit (LTT)
>
> I don't know what this buys us.

How about being able to:
- Debug synchronization problems among processes (there is no other
tool to do this, not gdb, not strace, not printf, ...)
- Measure exact time spent wainting for kernel and which other
processes a process had to wait for.
- Measure exact time it takes for an interrupt's effects to propagate
throughout the entire system.
- Understand the exact behavior the system has to input. (what is
the exact sequence of processes that run when I press a key).
- Identify sporadic problems in very saturated systems. (thousands
of servers and one of them is doing weird stuff).
- etc.

Providing system tracing is a necessity for any sort of complex
application development and system monitoring. Some people simply
can't use Linux without this sort of tool and I am at pains to
explain to them why they actually have to patch their kernel to
be able to debug their inter-process synchronization problems.

Users don't have to patch their kernel to use gdb and I don't
see why they should need to patch their kernel to understand how
their various processes interact with the kernel and vice-versa.

Karim

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Karim Yaghmour
karim@opersys.com
Embedded and Real-Time Linux Expert
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